Surgery using laparoscopic procedures is gaining popularity among surgeons due to patient demand for less invasive surgery. Electrosurgical or electrocautery devices are well known for use in cutting and coagulating tissue. A common use of these devices laparoscopically is in a procedure called cholecystectomy, or gallbladder removal. There have been some reported instances of injuries caused by such use of known electrosurgical devices. One known potential injury is organ burn, which may occur with inadvertent direct contact of the tip of the instrument with the organ or when an electrical charge from the device jumps or sparks to the organ.
Electrosurgical devices have heretofore included an insulated barrel that terminates in an electrically conductive dissection tip extending outward from the distal end thereof. The dissection tip is in electrical communication with a monopolar electrosurgical generator (ESU). These ESU's typically generate two types of radio frequency electrosurgical waveforms; namely, a "Cut" and a "Coag" waveform. It is known to provide electrosurgical devices with means to selectively irrigate or flush the surgical site with liquids and vacuum means to selectively remove excess body fluids and irrigation liquids from the surgical site.
In order to protect the dissection tip it is known to provide a tubular shield member that slips over the distal end of the barrel in surrounding relationship with respect to the dissection tip. Prior to use, it is necessary to remove the tubular shield member. Upon removal of the shield member and insertion of the barrel through a trocar tube during a laparoscopic procedure, the surgeon no longer has the ability to cover or shield the dissecting tip. As alluded to above, an unshielded dissecting tip may cause damage to body organs. Also, insertion and extraction of an unshielded tip may cause damage to the seal members associated with the trocar assembly.
It has heretofore been proposed to protect the dissection tip by providing a remote means to retract the dissection tip. This device includes structural elements located in the barrel that preclude use of the barrel to direct instruments therethrough.
There is a need for an electrosurgical device that includes a retractable electrode sheath that may be remotely and selectively controlled by the surgeon to protect the dissection tip and the trocar assembly seal during insertion and retraction and to protect body organs during surgery. There is further a need for an electrosurgical device that may be operated with one hand and that may accept instruments therethrough. There also is a need for an electrosurgical device that is safe and reliable in operation and economical to manufacture.